Furnace crucible



Aug. l0, 1926. 1,595,969

M; UNGER FURNACE CRUCIBLE FiledApril 18, 1922 2 sheets-sheet 1 i rig.l.'- 7 H34.

Ang'. 10,1926.

, M. UNGER FURNACE CRUCIBLE Filed April 18, 1922 2 sheetssheet 2 Fig. 6.

Inventar: magnus Unger;

Patented Aug. 10, 1926.

UNiTED STATES PATENT OFFICE.fi-@i HAGNUS UNGEB,

or PITTSFIELD, MASSACHUSETTS, A'ssroNoK'ro onNEnAn'ELEc- Tmc COMPANY, AconronA'rIoN or Nnw max. y s

rUnNAcE cnUcIiBLE.

The present invention com rises a new refractory container' or cruci lewhich is particularly well adapted for induction fur- IlHCeS.

Heretoiore, furnace crucibles, particularly when providing channels forthe circulation of charge, have been constructed by tamping therefractory material in a comminuted state mixed with a binder in a moldcontaining ya core which could be removed by 'fusion or combustion.yThis method O construction required time-consuming drying and baking oflarge' mass to whlch the air had little or no access and which could notreadily be handled or transported.

In accordance with my invention I have provided a crucible consisting ofacplurality'.

of preformed members which are a apted to be assembled in telescopingrelation in proper position with respect to the other parts of the'furnace. These members can be made and kept in reserve in an quantity,and when aembled permito the immediate resumption of furnace operation.The novel features of my invention will be ointed out with particularityin the appen ed claims.

1 have illustrated in the accompanying drawings two embodiments of myinvention ,constituted by crucibles for induction fur- 0 naces each ofwt ich is provided with a main reservoir and a communicating channel inwhich the charge is subjected to heating by induced currents.

Fig. 1 of the drawings is a vertical section of an induction furnacecontaining a cruci. blc constructed in accordance with my invention;Fig. 2 is a vertical section of the cruciblc with the members partlydisengag-cd; Figs. 3 and 4, respectively, represcnt a. vcrtical sectionand a plan vicw of an assembled crucible.; Figs, 5 and G, respectively,constitute an elevation and a vertical section oi a modiication.

A substantially complete induction fur nace has been shown in Fig. 1 tomake plain the relation of the `various parts. The furN nace comprises amagnetic, corc 1 upon which is mounted a primary windingl. The secondaryis constituted by thc. charge contained-within a cylindrical channel 3surrounding the core 1 and axially displaced with respect to the primarywinding 2, thereby causing by electromagnetic repulsion a circulation ofmolten charge l'ictwccn thc channel 'und thc reservoir 4 through theconduits 5, 6. This arrangement.yofl the primary and secondary windingsconstitutes no part oi"y my present invention. Fig. y1 A"i also for thesake otrcompleteuessshows a cover 7, a chargingdoor Banda-.spout 9, butthese are partswith ywhich` myA invention is not concerned. A. heat;insulatingllayer 1() has been diagrammatically indicated.

The furnace-body or Crucible-, as best shown in Figs. 2 and; comprisestubulaimembers 11, 12 adapted to be ncstedto proevide a hollow framee-'ltoo ed channel fand also a pot or reservoir 13 a apted .to/'engagewith the channel with its major-exisat right angles to the major axis ofthe'members 1li,

cess 14 and a flange 15 upon th`e-j1nterior surface located respectivelyat oppositeends. i.

gage with' the recessM and the l,flangepl at with the recess '17- astrongcompact-strtleture is produced. ,Themembers11,12iandi 13 mayconsist of tire brick, ortoth'ergsuitable refractory, materiah' and-aremoldedend fired by the usual methods. A liest"shoiv'vnin Figs. 3 and4, the. upper surface? effi/.he member 12 isrecessed-to @receivegtheresem voir 13, the joint ,beingy cemented upon gas sembly as indicated`at'18.; g

A preferred method of fcemnting the parts of a crucible consistingoftire brick\is carried out'as follows: A quantity of fire clay or cementrcndcrcd plastic by water is introduced at the shoulder or angle of thejoint. The parts to bc, ccnicutcd are brought together. Into the spaceremaining between the parts, as for example, the space remaining betweenthc cylindrical members 11 and l2. dry particles of burnt tire brick areintroduced which mix with the plastic clav absorbing;r a large part ofthe moisture. prefer to` use particles passingr 11 to 1/8 inch meshscreen.' These particles are rammed in firmlyaud the joint then may befired mn'iediately. This method avoids cracking and honey-combing of thecemcnt and results in a. substantially homogeneous cruciblc` Fig. 1shows at 19 an external clamp for one part of the joint where noshoulder has been provided to insure that no leaka *e of charge shouldoccur. As shown in 'Fig-s. 5

and G the clamp may be constituted by steel straps held together bysteel bolts 20. Other and additional clamping means may of course be emloyed.

Figs. 5 an G illustrate a crucible for an induction furnace in which themembers 2Q, :23 'are telescopically jointed to provide a looped channelwhich communicates at opposite ends with the space Within the reservoir24. An external clamp has been provided as in the crucible shown in Fig.1.

il furnace crucible constituted of preformed, interlocking or jointedunits may be made of refractory material having properties best suitedfor the desired service without reference to their adaptability to tamping into a mold, extra parts properly fired may be kept in stock so thatin case of a break in the Crucible repairs may be made promptly.

What I claim as new aud desire to secure by Letters Patent of the UnitedStates, is

1. An electric furnace Crucible comprising a plurality of members whichwhen nested. are in contact at separat-ed regions and being shaped toprovide a looped channel intermediate said regions of contact.

2. An induction furnace crucible comprising members consisting orpreformed refractory material, said members being engage-- able with oneanother to rovide a channel which is Izlosed upon itseli).

3. An induction furnace crucible comprising separable refractory memberswhich when 1n engagement provide a hollow, annular body having inlet andoutlet openin $4.8 An electric induction furnace Crucible comprising aplurality of preformed members ltelescopically joined with one anotherbut otherwise spaced apart to provide a channel.

5. An induction furnace Crucible comprising a plurality of nestedcylindrical. members joined at their pcripheries but otherwise separatedby a space which provides a charge-receiving c incl, and a con tainerfitted to seid mer-wis and communieating with said channel.

G. An induction furnace cruoible cour prising a plurality of cyiindricainieml-ers, the inner periphe y one mein ber being sealed to (he outerperipl'icry of the other member at opposite ends1 said members otherwisebeing separated by a space a third cylindrical member fitted to the sidewall of the outermost of said nested members and conduite connecting thespace between said nested members with the space within said cylindricalmember.

7. An induction furnace crucible comprising a cylinder of refractoryvmatr-.rial haring a recess and a. Hangs respectively :1t opposite endson the inte ior surface, a second cylinder' haring a recess and a iangcrespectively.:upon the exterior surface, the,l [lange ot' one cylinderengaging with the recess ot another cylinder spacing apart saidcylinders to'provide an annular charge1 receiving channel, and a thirdcylinder cngaging with said first-named cylinder with the major axis atright angles to the major axis of said nested cylinders, andcommunieating with said annular charge-receiving channel.

In witness whereof, l have hereunto set my hand this 17th day of April,

MAGUS UNSER.

Gli

